Set the CPU switch to STOP , then move it to MRES and hold for ~3 seconds until the STOP LED blinks. Release and immediately move it back to MRES for another 3 seconds. This factory resets the CPU, erasing the program and the password.
Use a hex editor (HxD/010 Editor) with the Siemens MMC template. Look for the 0x53495F41 ("SI_A") header. The blocks start at offset 0x1000 . unlock and converter mmc image s7
Do you already have an or are you trying to read the physical card ? Set the CPU switch to STOP , then
pip install s7utils s7_mmc_unlock --input locked_image.bin --output unlocked_image.bin --force Set the CPU switch to STOP
